Feeding mechanism for rock drills



March 30, 1937,

J. CVCURTIS FEEDING MECHANISM FOR ROCK DRILLS I Filed May 24, 1955 5 Sheets-Sheet l mum- JOHN a bu? 77s INVENTOR ATTORNEY March 30, 1937. J. c. CURTIS 2,075,572

FEEDING MECHANISM FOR ROCK DRILLS Fild May 24, 1955 3 Sheets-Sheet 2 March 30, 1937. J. c. CURTIS FEEDING MECHANISM FOR ROCK DRILLS Filed May 24, 1935 s she ts-sheet 5 B Iv 0 7 #5 .a 1 a v 7!? {ivy/J a. Na Na m an Q \swmk WH P- l I] II. I l l l l l IH PHFHEHFFFFI l ATTORNEY Patented Mar. 30, 1937 FEEDING MECHANISM FOR ROCK DRILLS John C. Curtis, Garfield Heights, Ohio, assignor to The Cleveland Rock Drill Company, Cleveland, Ohio, a corporation of Ohio Application May 24, 1935, Serial No. 23,213

23 Claims.

This invention relates broadly to feeding mechanism, but more particularly to a fluid actuated feeding mechanism for rock drills of the drifter type.

One object of this invention is to produce an improved and compact feeding mechanism for rock drills, wherein the rock drill is adapted to travel at the same rate of speed as that of the feeding element, and wherein the overall length of the assembly is materially shorter than that of similarly actuated feeding mechanism of equal feeding range.

Another object of this invention is to produce a fluid actuated feeding mechanism for rock drills with a device automatically operated for checking the recoils of the rock drill imparted thereto due to the reversal of the piston stroke within the latter.

Another object of this invention is to provide a motive fluid actuated mechanism for rock drills of compact and sturdy construction, wherein the movable parts of the mechanism are efiioiently guided against lateral movement irrespective of their relative position.

Other objects and advantages reside in the specific construction and aggroupment of the elements peculiar to this structure as will become apparent from a more complete examination of this specification, in the claims of which there 30 are assembled certain specific combinations of parts and specific construction indicative of the scope and spirit of the invention.

In the drawings:

Fig. 1 is a longitudinal view showing the drilling 35 motor at one extreme end of its travel, the feeding mechanism being shown in section to illustrate details of construction.

Fig. 2 is a view similar to Fig. 1 illustrating the drilling motor at the other extreme end of its 40 travel.

Fig. 3 is an enlarged sectional view of a portion of the feeding mechanism shown in Figs. 1

and 2.

Fig. 4 is a sectional view taken in a plane indicated by line 4-4 in Fig. 3.

Fig. 5 is an enlarged cross sectional view taken in a plane indicated by line 55 in Fig. l and looking in the direction of the arrows shown 50 therein.

Fig, 6 is a longitudinal sectional view taken in a plane indicated by line 6-45 in Fig. 5, illustrating one end portion of the mechanism.

Figs. 7, 8, and 9 are enlarged cross sectional 55 diagrammatical views taken in a plane indicated by line 1-1 in Fig. 6, and illustrating the throttle valve in different positions.

Fig. 10 is an enlarged sectional view taken in a plane indicated by line Ill-10 in Fig. 5.

Fig. 11 is an enlarged cross sectional view taken in a plane indicated by line Ill| in Fig. 1, and looking in the direction of the arrows shown therein.

Fig. 12 is a plan view of the complete assembly.

Fig. 13 is an enlarged cross sectional view taken in a plane indicated by line I3l3 in Fig. 1.

, Fig. 14 is a longitudinal sectional view taken in a plane indicated by line I l-I4 in Fig. 2.

Fig. 15 is a cross sectional view taken in a plane indicated by line I5-l5 in Fig. 13.

Fig. 16 is also a cross sectional view taken in a plane indicated by line l6|6 in Fig. 13.

Referring to the drawings in which like symbols designate corresponding parts throughout theseveral views, 20 designates a stationary elongated shell or support having the usual cone 2| depending therefrom. The shell is formed with the usual guideways 22 extending the full length thereof and adapted to slidably receive guides 23 which are welded or otherwise aflixed to the side walls of a substantially rectangular tube 24, which is slidable relative to the shell 2|]. Secured to the upper wall of the tube 24 by means of a weld 25, there is a duality of elongated members 26 having a guideway 21 extending the full length thereof, and adapted to receive the guides 28 of a drilling motor 29.

Rigidly secured into the tube 24, there are two plates or partitions 30 and 3|, the former being affixed in the front end portion thereof by means of a weld, while the latter is located in substantially equidistant relation with the ends of the tube and is removably secured therein by cross bolts 32. The upper wall of the tube 24 located rearwardly of the partition 3| is slotted as at 33 to permit the free slidable movement of a tongue 34 leading from the interior to the exterior of the tube 24, and constituting an integral portion of a l back head 35 which is secured to the motor 29 by side rods 36. Secured to the tongue 34 by a nut 31, there is one end of a piston rod 38 which extends therefrom through the partition 3| into the space located between the partitions 30 and 31, hereinafter denoted as piston chamber 39. The end of the piston rod in the pressure chamber 39 has mounted thereon a piston 40 having packing members 4| assuring a fluid tight joint between the piston and the inner wall of the tube. Surrounding the piston rod 38 but in spaced relation therewith, there is a tube 42 clamped between the tongue 34 and piston 49. To assure a fluid tight joint between the partition 3|, the inner wall of the tube 24 and the external wall of the tube 42, the partition is equipped with packing members 43 and 44 secured thereto by bolts 45.

The front end portion of the tube 24 has the upper and lower walls thereof provided with a slot similar to the slot 33. Transversally mounted therethrough, there is a shaft 46 having a sprocket wheel 41 rotatable thereon and protruding above and below the tube 24. This sprocket wheel is adapted to receive a flexible member or chain 48 having one end attached to the back head 35 by a cross pin 49, while the other end thereof is similarly afiixed to the front end of the support 20 by a pin 59.

The back end portion of the tube 24 has the lower wall thereof cut away to permit the introduction of two housings and 52 which are secured to the side walls of the tube 24 by bolts 53. Disposed between these two housings which extend somewhat belowthe lower wall of the tube 24, there is a sprocket wheel 54 locked on a shaft 55 by a key 56. This shaft extends into the housings 5| and 52 for rotation therein. The sprocket wheel 54 protrudes through the opening 33 provided in the upper wall of the tube, and is adapted to receive a chain 5'! which has one end attached to the tongue by a pin 58, while the other end of the chain is fastened to a bolt 59 by a pin 59. This bolt is slidably mountedthrough a lug 6| depending from the rear end of the support 29, and may e adjusted longitudinally to regulate the tension of the chains 48 and 5'! by means of nuts 62.

The housing 5| is conveniently machined to rotatably receive a ratchet ring 63 having ratchet teeth 64 cut in the peripheral wall thereof and smaller teeth 85 cut in its inner wall. Engageable with the teeth 54 there is a plunger 65 formed with a head 67 slidably mounted within a chamber 68 which is closed at one end by a plug 63. The plunger 63 is urged in engagement with the teeth 64 by a compression spring 19 interposed between the plunger head 6'! and plug 69. Leading from the bottom of the chamber 68 beneath the plunger head Bl there is a passage 1 I, which is in constant communication with a small tube 12. This tube opens into the piston chamber 39 adjacent the wall or partition 39. Locked on the shaft 55 by the key 55, there is a disk like member 73 located inside the ratchet ring 53 for rotation relative thereto. This disk is conveniently machined to receive two pawls l4 engageable with the teeth 65 of the ring 63. Each pawl is urged in engagement with the teeth 65 by a spring pressed plunger 15 slidably mounted within the disk 13. The ratchet ring 53 and disk 13 are maintained in the housing 5| against longitudinal movement therein by a bearing plate 16, which is disposed within the housing 5| between the ratchet ring 63 and sprocket wheel 54.

Within the housing 52, there is a mechanism which is a replica of the mechanism incorporated in the housing 5|. It comprises a ratchet ring Tl formed with external teeth 18 and internal teeth 19. The teeth 18 are also adapted to receive a plunger 89 having a head 8| slidable within a chamber 82 which is closed by a plug 83. The plunger 89 is also urged in engagement with the teeth 18 by a compression spring 84, while the bottom of the chamber 82 is in constant communication with the pressure chamber 33 at a place adjacent the partition 3|, by a tube 85 and passage 86. Within the ratchet ring 11 is also rotatably mounted a disk 81 locked on the shaft 55 by the key 56, and thereby rotatable with the disk 13 and sprocket wheel 54. The disk 81 also carries pawls 88, which are urged in engagement with the teeth 79 by a spring pressed plunger 89. While the mechanism in the housing 52 is a replica of the one in the housing 5|, the ratchet ring 11 in the housing 52 is introduced therein so as to position the teeth 78 of the latter in opposition to the teeth 64 of the ratchet ring 53, and the disk 81 is also introduced in the ring 11 to position the pawls 88 in opposition to the pawls 74.

The back head 35 of the rock drill 29 is provided with a cylindrical transversally disposed chamber 90 having one end portion thereof machined to receive an inlet motive fluid connection 9|. Rotatably mounted Within the chamber 98, there is a throttle valve 92 extending to the exterior of the back head to receive a handle 93. The throttle valve is formed with a central bore 94 in constant communication with the connection 9|, and a radially disposed port 95, by which the throttle valve bore 94 may be put in communication with a port 98, formed in the back head 35. This last port leads into an enlarged chamber 91 provided within a bearing plate 98, the latter being located within the motor 29 in abutting engagement with the back head 35. From this last chamber motive fluid is admitted into the drilling motor 29 for actuating the same. Within the bearing plate 98, there is another chamber 8 having motive fluid constantly admitted therein through a passage 5 l9 which opens in the throttle valve chamber 99.

Rotatably mounted within the back head 35, there is a tapered feed controlling valve 99 having a handle E90 keyed thereon for operating the same. This handle is formed with a flange iiH having V-shaped grooves I92 cut on the back face thereof and adapted to receive the correspondingly shaped end of a spring pressed plunger |93 slidably mounted within the head 35. This tapered valve is formed with a central bore I94 in constant communication with the chamber H8 of the bearing plate 98. Leading radially from the bore 94 and located within the same transversal plane, the tapered valve 99 is provided with two ports I55 and H33, the latter having a relatively long V-shaped groove I91 leading therefrom to the periphery of the valve. In opposition to the ports !95 and I85, the circumferential wall of the tapered valve is machined to provide a relatively large groove H38, which is in constant communication with a port I99 formed in the back head 35 and opening to the atmosphere between the back head and the tube 24. From the tapered valve 59 motive fluid may be admitted into a port H9 formed in the back head 35 and tongue This port is in communication with an annular recess ||2 formed in the tongue 34 around the piston rod 38. From this recess the fluid may flow between the piston rod 38 and tube 42 into the piston chamber 39 of the tube 24 through a port 3 formed through'the tube- 42 behind the piston 49. The piston rod 38 is formed with a centrally disposed port I I4 opening into the pressure chamber 39 ahead of the piston 49. This last port is in communication with the tapered valve 99 through a passage l|5 radially disposed through the piston rod 38, and a passage 5 l6 formed in the tongue 34 and head 35. Leading from the port H9, there is a relatively small vent capable of communication 4 nism, let us assume that the throttle valve 92 is positioned to cause the communication of the port 95 with the port 96 for admitting motive fluid into the groove 97, from where it will'flow into the motor 29 for actuating the same, and let us further assume that the tapered valve 99 is positioned as shown in Fig. 8, that is with the ports H35 and N8 out of communication with either the port [it or H6. In this neutral position of the tapered valve 99, it will be noticed that no pressure fluid is admitted into the pressure chamber 39 of the tube 2Q, thus allowing the engagement of the plunger 66 with the teeth 34 of the ratchet ring 53 and the similar engagement of the plunger 8G with the teeth E8 of the ratchet ring 'l'i. Since the disk 73 keyed to the shaft 55 is prevented to rotate in one direction due to the engagement of the pawls i l with the teeth 55 of the ring 53, and the disk 8'! also keyed to the shaft 55 is prevented to rotate in the other direction due to the engagement of the pawls 88 with the teeth IQ of the ring Tl, it will be understood that the sprocket wheel 54 also keyed to the shaft 55 will thus be prevented to rotate in either direction, thereby preventing the longitudinal movement of the drilling motor 29 in either direction due to the chain 51 engaging the now stationary sprocket wheel When tapered valve 99 is rotated in a counterclockwise direction, the port iiili through the V groove ill! will be moved in communication with the port Hi3. In this instance, a limited amount of motive fluid is admitted into the piston chamber 38 through the port Hi3, annular recess H2, the clearance between the piston rod 38 and tube 42, and the port H3. The motive fluid thus admitted in the piston chamber 39 between the partition 3i and piston All will flow therefrom through the tube 85 into the plunger chamber 82 via the port 85, thus acting under the head 8| to lift and maintain the plunger 36 out of engagement with the teeth 18 of the ratchet ring Tl against the effort of the compression spring 3 3, and thereby permitting the rotation of the ratchet ring l? in a clockwise direction. In this instance, the engagement of the pawls 88 with the teeth 19, will not prevent the rotation of the disk 87, since the ratchet ring is now free to rotate in that direction. The piston 49 subjected to the action of the motive fluid in the chamber 39 will be driven in the forward direction. The drilling motor 29 being rigidly connected to the piston 53 by the pistcn rod 38 will also move forwardly at a rate of speed equal to that of the feeding element or piston to. The chain 5'! connected to the drilling motor will obviously cause the rotation of the sprocket wheel 5-; in a clockwise direction, which is now permitted since the plunger 8% is maintained out of engagement with the teeth '58 of the ring 'l'l. During this free rotation of the sprocket wheel 54, the disk 13 is also rotated in the same direction with the pawls M riding the teeth 65 of the now stationary ratchet ring 63. However the engagement of these last pawls with their corresponding teeth, will prevent the rotation of the disk 13 and consequently of the sprocket wheel 5% in a counterclockwise direction, thus checking the recoils or longitudinal move ment of the drilling motor in a direction adverse to that of its feeding motion. The chain 51 passing over the sprocket wheel 54 and having one end aflixed to the stationary support 26, will, when moved forwardly by the motor 29, transmit longitudinal slidable movement to the tube 24 relative to the support 20. Obviously the rate of speed of the tube 24 will be equal to one half of that of the drilling motor 29 or piston 40. It will now be understood that since the tube 24 travels with the drilling motor at a rate of speed equal to one half of that of the latter, the total travel of the motor is equal to twice the distance shown in Fig. 1 between the piston 40 and partition 39, p

The amount of motive fluid admitted into the piston chamber 39 may be regulated by causing a more or less complete communication of the tapered valve port H15 with the port Illl. It will be noted that when the motive fluid is admitted into the port H9 through the restricted portion of the -groove till, the relatively small Vent or port i ll leading from the port I I0, is still in communication with the exhaust port H19 through the valve groove Hi8, thus preventing the pressure of the motive fluid within the pressure cham ber 39 to build up, and consequently affording a relatively slow and constant feeding speed of the motor as. It will be noted that in the neutral position of the tapered valve and when motive fluid is admitted into the rear end portion of the pressure chamber 529, the motive fluid previously admitted into the forward end portion of this chamber is free to exhaust to the atmosphere through the piston rod port l M, passages I I5 and H6, valve groove I88 and exhaust port I09, permitting thereby an unrestricted forward movement of the piston i l) within the piston chamher 3%.

When it is desired to feed the drilling motor away from the work, the valve 99 may be positioned as shown in Fig. 9. In this position of the valve, the motive fluid previously admitted into the rearward portion of the piston chamber 39 is now free to exhaust therefrom through the passage H3, the clearance between the pise ton rod 38 and tube :22, the annular recess H2, port ill], valve groove I63 and exhaust port Hi9. Simultaneously the motive fluid admitted in the plunger chamber 82 is now free to exhaust therefrom through the ports 85 and tube 85, thus permitting the re-engagement of the plunger 80 with the teeth 78 of the ratchet ring Ti to prevent the rotation of the latter. Simultaneously motive fluid is admitted into the front portion of the piston chamber 39 through the valve port H35, passages lit and H5, and the piston rod port lid. From the front portion of the piston chamber 3%, motive fluid will flow through the tube 52 and passage H into the plunger chamber 68 formed in the housing 5!, for lifting and maintaining the plunger 6S out of engagement with the teeth cc of the ratchet ring 63, and thereby permitting the rotation of the latter. The motive fluid admitted in the front end portion of the piston chamber 39 will act on the front face of the piston iii-to drive the latter, and consequently the drilling motor 29, rearwardly or away from the work. The rearward longitudinal movement of the motor 29 imparted to the chain 48 which passes over the sprocket wheel 37 and has one end fastened to the stationary support 2i will cause the rearward slidable movement of the tube 24 relative to the support 2E at a rate of speed equal to one half of that of the motor 23. This slidable movement of the tube 2 will obviously cause the rotation of the sprocket wheel 54 in a counterclockwise direction in Fig. 15, which rotation is permitted since the ratchet ring 63 is now free to rotate. The rotation of the sprocket wheel 54 is also transmitted to the disk 81 by the key 56,

thus causing the pawls 88 to ride the teeth 19 of the ratchet ring ll. The recoil or longitudinal movement of the drilling motor 29 in a forward direction, is now prevented by the end engagement of the pawls 88 with the teeth 19 of the ratchet ring ii, the latter locked against rotation by the engagement of the plunger 89 with the teeth 18.

When the tapered valve 98 is again positioned as shown in Fig. 8, the motive fiuid previously admitted in the front end portion of the piston chamber 39, is now free to exhaust therefrom through the piston rod l M, passages E5 and i it, valve groove Hi8 and exhaust port I09. Simultaneously the motive fluid previously admitted into the plunger chamber 68, is now free to exhaust through the passage 7'! and tube 12, thus allowing the re-engagement of the plunger 66 with the teeth 64 of the ratchet ring 53, and thereby looking the drilling motor against longitudinal movement in either direction.

From the foregoing, it will be understood that in the present construction, the drilling motor is fed toward or away from the work at a rate of speed equal to that of the feeding element. It will also be understood that due to the travel of the tube 2%, the total feeding range of the drilling motor is materially greater than the length of the piston or pressure chamber 39, thus materially reducing the overall length of the entire assembly.

Although the foregoing is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining, and it is to be further understood that various re-arrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. In a drilling apparatus, the combination with a stationary support, of a tube slidable thereon, a drilling motor slidable on said tube, a piston chamber within said tube having a fluid actuated piston reciprocable therein and rigidly connected to said motor for imparting feeding motion thereto, and connecting means between said motor and tube whereby feeding motion of the former is transmitted to the latter at a lesser rate of speed.

2. In a drilling apparatus, the combination with a stationary support, of a tube slidable thereon, a drilling motor slidable on said tube, a pressure chamber within said tube having a fluid actuated piston reciprocable therein and connected to said motor for imparting feeding motion thereto relative to said tube, and means deriving motion from the feeding motion of said motor for transmitting motion to said tube in the same direction but at a lesser rate of speed than that of said feeding motion.

3. In. a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a feeding mechanism for said motor including a piston reciprocable within said housing, means for effecting relative motion between said housing and piston and for transmitting said motion to said motor, and means deriving motion from said relative motion for transmitting motion to said housing in the same direction but at a lesser rate of speed than that of the relative motion aforesaid.

4. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a feeding mechanism for said motor including a piston connected to said motor and reciprocable within said housing, means for admitting motive fluid into said housing for effecting the reciprocation of said piston and thereby effecting relative motion between said motor and said housing, and means deriving motion from said relative motion for transmitting motion to said housing in the same direction but at a lesser rate of speed than that of the relative motion aforesaid.

5. In a drilling apparatus, the combination with a stationary support, of a feeding mechanism slidable thereon comprising a slidable elongated housing having a piston slidable therein, a drilling motor slidable on said housing, means for transmitting the slidable movement of said piston to said motor at an equal rate of speed, and means for transmitting the slidable movement of said motor to said housing at a different rate of speed.

6. In a drilling apparatus, the combination with a stationary support, of an elongated housing sl dable thereon, a drilling motor slidable on said housing, a feeding mechanism for said housing and motor comprising a piston slidable within said housing, and means for transmitting the slidable movement of said piston to said motor at an equal rate of speed and to said housing at a lesser rate of speed.

'7. In a drilling apparatus, the combination of a stationary support having an elongated housing carried thereby, a drilling motor carried by said housing, said housing and motor being capable of slidable movement relative to said support in the same direction but at a different rate of speed, a power actuated element within said housing, and means deriving motion from said element for effecting the slidable movement of said housing and motor relative to said support in the direction and at the different rate of speed aforesaid.

8. In a drilling apparatus, the combination with a stationary support, of an elongated element slidable thereon, a drilling element slidable on said elongated element, a feeding mechanism including a feeding member slidable within one of said elements, and means deriving motion from the slidable movement of said feeding member for transmitting longitudinal motion to one of said elements at a rate of speed equal to that of said member, and to the other of said elements at a lesser rate of speed.

9. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a feeding mechanism including a feeding element slidable within said housing, connecting means between said element and said motor for transmitting the slidable movement of the former to the latter, and other connecting means between said support and said motor associated with said housing and deriving motion from the slidable movement of said motor for transmitting slidable movement to said housing.

10. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a feeding mechanism comprising a feeding element slidable within said housing, a connection between said element and said motor for transmitting the slidable movement of the former to the latter, and a flexible draft element operatively associated with said housing and deriving motion from the slidable movement of said feeding element for transmitting slidable movement to said housing.

11. In a drilling apparatus, the combination with a stationary support, of a tube slidable thereon, a drilling motor slidable on said tube, a piston element slidable within said tube, and slidable movement transmitting means operatively associated with said piston, said motor, and said tube for transmitting the slidable movement of said piston to said motor and tube in the same direction as that of said piston but at a different rate of speed between said motor and tube.

12. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, of a motor slidable on said housing, a piston slidable within said housing, passages for admitting motive fluid into said housing for effecting the slidable movement of said piston, a connection between said piston and motor for transmitting the slidable movement of the former to the latter at an equal rate of speed, a flexible member between said motor and said housing for transmitting the slidable movement of the former tothe latter at a different rate of speed, and means operatively associated with said flexible member and automatically operable for preventing the slidable movement of said motor in a direction adversed to that of the slidable movement transmitted thereto from said piston.

13. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a power actuated feeding device operatively associated with said housing and motor for imparting slidable movement thereto, a

mechanism associated with said motor and housing for transmitting the slidable movement of the former to the latter at a different rate of speed, and means operatively associated with said mechanism automatically operable for checking the movement of said housing and motor in a direction adversed to that of the slidable movement imparted thereto by said feeding device.

14. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a power actuated feeding mechanism operatively associated with said motor for imparting slidable movement thereto, a rotatable member carried by said housing having a flexible draft element associated therewith and with said motor whereby the slidable movement of the latter is transmitted to said housing, and means operatively associated with said member and automatically operable for preventing the rotation thereof in one direction, preventing thereby the slidable movement of said housing and motor in a direction adversed to that of the slidable movement imparted thereto by said feeding mechanism.

15. In a drilling apparatus, the combination with a stationary support, of an elongated housing slidable thereon, a drilling motor slidable on said housing, a feeding element slidable within said housing, mean for effecting the slidable movement of said element, a connection between said element and said motor for transmitting the slidable movement of the former to the latter, a mechanism associated with said motor and housing for transmitting the slidable movement of the former to the latter at a different rate of speed, and means associated with said mechanism automatically operable for preventing the slidable movement of said housing and consequently of said motor in a direction adversed to that of the slidable movement transmitted to the latter from said feeding element and irrespective of the sense of direction of the latter.

16. In a drilling apparatus, the combination with a stationary support, of a drilling motor slidable with respect to the support and having motive fluid admitted the-rein, of a fluid actuated feeding mechanism for said motor including a duality of slidable elements telescopically mounted between said support and motor, a rigid connection between one of said elements and said motor for transmitting feeding motion to the latter, means including passages within said connection for admitting motive fluid from said motor into said feeding mechanism for actuating said element, and connecting means between said motor and the other of said elements whereby feeding motion of the former is transmitted to the latter at a rate of speed different from that of said motor.

17. In a drilling apparatus, the combination with a stationary support, of a drilling motor slidable with respect to the support and thereby having motive fluid admitted therein, of a fluid actuated feeding mechanism for said motor including a duality of slidable elements telescopically mounted between said support and motor, a rigid connection between said motor and one of said elements and connecting means including a flexible member between said motor and the other of said elements whereby feeding motion is transmitted from one of said elements to said motor and therefrom to the other of said elements at a rate of speed different from that of said motor, and means including passages within said rigid connection for admitting motive fluid from said motor into said feeding mechanism for actuating the same.

18. In a drilling apparatus, the combination with a stationary shell, of a drilling motor slidable with respect to the shell and having motive fluid admitted therein, of a fluid actuated feeding mechanism for the motor including relatively slidable cylinder and piston elements, said cylinder element being guided by said shell and having said motor slidably guided thereon, a connection between said piston element and said motor for transmitting slidable movement from the former to the latter, means including one passage within said connection for conveying motive fluid from said motor into said mechanism for actuating the same, and speed reducing connections between said motor and said cylinder element.

19. In a drilling apparatus, the combination with a stationary support, of a tube slidable thereon, a drilling motor slidable on said tube, a piston slidable within said tube rigidly connected to said motor for transmitting slidable movement thereto, passages for admitting motive fluid into said tube for actuating said piston, a transmission mechanism for transmitting slidable movement from said motor to said tube, and means within said mechanism operable for checking the movement of said motor in a direction adversed to that of the slidable movement imparted thereto by said piston.

20. In a drilling apparatus, the combination with a stationary support having a drilling motor carried thereby, of a feeding device for said motor including slidable piston and cylinder elements, movement transmitting means between one of said elements and said motor, a speed reducing mechanism between said motor and the other of said elements, and means within said mechanism automatically operable for checking the movement of said motor in a direction adversed to that of the movement thereof resulting from said feeding device.

21. In a drilling apparatus, the combination With a slidable drilling motor, of a feeding mechanism for said motor including a motor carrying element and a fluid actuated piston slidable therein, of a stationary support upon which said element is slidably mounted, and means for transmitting motion from said piston to said motor and from the latter to said element including a rigid connection between said piston and motor and a speed reducing mechanism between said motor and element.

22. In a drilling apparatus, the combination With a slidable drilling motor, of a shell slidably carrying said motor, of a stationary support slidably carrying said shell, and means for'imparting slidable motion to said motor and shell including a fluid actuated piston slidable within said shell rigidly connected to said motor and a flexible element connected to said motor and support operatively associated with said shell for transmitting thereto the slidable movement of the motor at a slower rate of speed;

23. In a drilling apparatus, thecombination with a stationary support, of a tube slidable thereon, of a drilling motor slidable on said tube, of a piston slidable within said tube rigidly connected to said motor for transmitting slidable movement thereto, a transmission mechanism, for transmitting slidable movement from said motor to said tube, and means within said mechanism for simultaneously locking said motor and tube against movement relative to said support;

JOHN C. CURTIS. 

